Double-acting hydraulic cylinders are known from the prior art. FIG. 8A shows a sketch of a known double-acting hydraulic cylinder 100. The known hydraulic cylinder 100 according to FIG. 8A comprises a cylinder housing 102 and a piston 104 guided in the cylinder housing 102 and a second pressure chamber 108 formed by the cylinder housing 102. The first pressure chamber 106 and the second pressure chamber 108 are separated from one another by the piston 104. The first pressure chamber 106 is also designated as cylinder chamber A while the second pressure chamber 108 is also designated as cylinder chamber B.
As FIG. 8A shows, the cylinder chambers 106, A and 108, B must be connected to a supply unit/control unit 110 which supply the hydraulic cylinder 100 with a liquid or gaseous medium. The connection between the supply unit/control unit 100 and the connector 112 and 114 on the cylinder housing 102 takes place via a flexible hose 116, 118. Typically, an annular eyelet 120 consisting of metal, a hollow screw 122 and two seals 124, 126 are attached on the particular hose end, as is schematically shown in FIG. 8C. FIG. 8C shows in particular a schematic view of an exposed hollow screw 122 of the known hydraulic cylinder 100 according to FIG. 8A. For the usage in operating tables a hose 116, 118 with a nominal width D3 and DN 4 are typically used. Furthermore, the screwing has a height L1 from the outer surface of the cylinder housing 102 to the end of the hollow screw 122 of about 15 mm. The hoses 116, 118 are necessary if the cylinder 100 shown in FIG. 8A is movably attached.
FIG. 8B shows a schematic view of a double-acting hydraulic cylinder 200 according to the prior art. FIG. 8B shows in particular a replacement part image of the double-acting hydraulic cylinder 200 of the construction series CSH1 MF3, MF4, MT4 and MS2 according to the Bosch Rexroth catalog with the catalog number RD17332/07.13. In double-acting hydraulic cylinders a connector for a liquid medium must be provided on the A side, i.e., the piston side, and on the B side, i.e., on the piston rod side. This is usually accomplished, as is shown in FIG. 8B, by a connector bore 212, 214 in the housing of the double-acting hydraulic cylinder 200.
The known, double-acting hydraulic cylinders have the disadvantage that to the extent that the cylinder 102 shown in FIG. 8A is used with the hose connectors 112, 114 in close structural spaces, the hollow screw 122 shown in FIG. 8C is very exposed and problematic. This is especially disadvantageous in that about 15 mm structural space in the length or the width of the hydraulic cylinder are lost. Furthermore, the known, double-acting hydraulic cylinders have the disadvantage that the exposed hollow screw 122 can be readily sheared off on close structural components during the hydraulic cylinders movement due to the high cylinder forces during the traveling movement. In addition, the hose connections 116, 118 shown in FIG. 8A in the known, double-acting hydraulic cylinders are relatively susceptible to being damaged.